Central Artery/Tunnel Project, South Bay Interchange
Boston, Massachusetts

DMJM+HARRIS is responsible for coordinating design elements for several segments of this project, and for final design of several major structural components. As subconsultant for the I-90 tunnels and the I-93 (northbound) bridge and transition tunnels, DMJM+HARRIS has recommended many innovative design options that have been incorporated by the Massachusetts Highway Department. Key among them are the use of the largest installation of “Japanese Deep Soil Mix” in North America, and the largest "jacked tunnel" sections in the United States. These innovative structural techniques have generated substantial savings in construction costs (approximately $350 million), while mitigating interference with Amtrak and the southside commuter rail line.

Confronted with a demanding project that entails several thousand feet of bridge work, viaducts, and tunnels-including tunnels under live, operating commuter tracks—DMJM+HARRIS developed solutions that stretch the limits of current design technology. Addressing everything from marine design and channel dredging to techniques for pile removal and demolition of old bridge structures, our integrated approach ensures that the completed project will give the commuting public an aesthetically pleasing, cost-effective, low-maintenance solution.